From e4e99208002708f4f809fdffc4fb254ea3c97a83 Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Mon, 20 Jun 2022 09:15:47 +0200
Subject: udmabuf: add back sanity check
Git-commit: 05b252cccb2e5c3f56119d25de684b4f810ba40a
Patch-mainline: v5.19-rc4
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 bsc#1210453 CVE-2023-2008
Check vm_fault->pgoff before using it. When we removed the warning, we
also removed the check.
Fixes: 7b26e4e2119d ("udmabuf: drop WARN_ON() check.")
Reported-by: zdi-disclosures@trendmicro.com
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/dma-buf/udmabuf.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index e7330684d3b8..9631f2fd2faf 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -32,8 +32,11 @@ static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct udmabuf *ubuf = vma->vm_private_data;
+ pgoff_t pgoff = vmf->pgoff;
- vmf->page = ubuf->pages[vmf->pgoff];
+ if (pgoff >= ubuf->pagecount)
+ return VM_FAULT_SIGBUS;
+ vmf->page = ubuf->pages[pgoff];
get_page(vmf->page);
return 0;
}
--
2.38.1